1. Field of the Invention
The present invention relates to a display device for vehicles, and more particularly, to a display device equipped with a light control device capable of adjusting the luminance of a light source according to the brightness of the surroundings.
2. Description of the Background Art
In an automobile or a motorcycle, a display device which displays vehicle speed, engine speed, etc. is provided with an illuminating system for illuminating a display surface, that is, an instrument panel surface. Some illuminating systems are fitted with a light control device which can detect the external light by a sensor and adjust the luminance of the light source in accordance with the detected output. However, it is likely that sensor characteristics will be deteriorated by heat, ultraviolet rays or infrared rays of the external light, resulting in inaccurate light control. To cope with this shortcoming, therefore, there has been proposed by Japanese Utility Model Publication No. 2582395 a head-up type display device which guides the external light to the sensor by a light guide body having a characteristic to cut the ultraviolet rays and infrared rays.
Generally, the sensor and the light guide member for the light control device are located in a place, for example on an instrument panel directly exposed to the external light, or, in a motorcycle, in the vicinity of a windshield supporting portion. Therefore, the display screen of the display device is sometimes shaded by the instrument panel or the light is reduced by a visor mounted above the display device even when the surroundings are bright. In such a case, if the luminance is adjusted according to the detected output of the sensor, the display screen is not necessarily bright to the rider (or driver).
It is therefore an object of the present invention to provide a display device for vehicles which is capable of accurately detecting the easy-to-view luminance on the display screen, and controlling the light according to a result of the detection.
To attain the above-described object, the display device of this invention has a light control means for controlling the illumination on the display surface according to the illumination detected by the light sensor.
The display device includes a case, an instrument panel housed in the case, and a lighting means for illuminating the instrument panel. The light sensor is located on the surface of the instrument panel. The light sensor for light control is disposed on the surface of the instrument panel for practical visual recognition by the rider (or driver). Because of the provision of the light sensor, the rider (or driver) can see results of measurements of the vehicle speed and others at an easier-to-recognize illumination.
The lighting means is disposed on the back side of the instrument panel, and a light shielding means is provided for shielding the light of the lighting means coming from behind the light sensor. The light from the lighting means can therefore be prevented from directly entering the light sensor.